selMod {pgirmess} | R Documentation |
Handles lm, glm and list of e.g. lm, glm, nls, lme and nlme objects and provides parameters to compare models according to Anderson et al. (2001)
selMod(aModel, Order = "AICc", ...) ## S3 method for class 'lm': selMod(aModel, Order = "AICc", dropNull = FALSE, selconv=TRUE, ...) ## S3 method for class 'list': selMod(aModel, Order = "AICc", ...)
aModel |
a lm or glm model or a list of relevant models (see details) |
dropNull |
if TRUE, drops the simplest model (e.g. y~1) |
Order |
if set to "AICc" (default) sort the models on this parameter, otherwise "AIC" is allowed |
selconv |
if TRUE (default) keep the models for which convergence is obtained (glm object only) and with no anova singularity (lm and glm) |
... |
other parameters to be passed as arguments (not used here) |
This function provides parameters used in the information theoretic methods for model comparisons.
A dataframe including:
LL |
the maximized log-likelihood |
K |
the number of estimated parameters |
N2K |
the number of observations/K |
AIC |
the Akaike index criterion |
deltAIC |
the difference between AIC and the lowest AIC value |
w_i |
the Akaike weights |
deltAICc |
the difference between AICc and the lowest AICc value; advised to be used when n2K < 40 |
w_ic |
the AICc weights |
The models examined from first to last are stored as attribute
Patrick Giraudoux and David Pleydell: pgiraudo@univ-fcomte.fr, dpleydel@univ-fcomte.fr
library(MASS) anorex.1 <- lm(Postwt ~ Prewt*Treat, data = anorexia) selMod(anorex.1) anorex.2 <- glm(Postwt ~ Prewt*Treat, family=gaussian,data = anorexia) selMod(anorex.2) anorex.3<-lm(Postwt ~ Prewt+Treat, data = anorexia) mycomp<-selMod(list(anorex.1,anorex.2,anorex.3)) mycomp attributes(mycomp)$models